A code to convert from numbers to English words, any improvements?

[Blockzez]

I’ve made a function that converts from numbers to English words (e.g. 100 to one hundred). It works but I need a better and more effiencint way of doing this, it supports numbers as strings. How can I improve this code?

function ToWord(value, context)
	    context = context or { financial = false; scale = 'long'; decimal = 0; };
	    context = { scale = context.scale or 'long'; decimal = context.decimal or 0; };
	    local numbers =
	    {
	        ones = { "one", "two", "three", "four", "five", "six", "seven", "eight", "nine", "ten", "eleven", "tweleve", "thirteen", "fourteen", "fifteen", "sixteen", "seventeen", "eighteen", "nineteen" };
	        tens = { '', "twenty", "thirty", "fourty", "fifty", "sixty", "seventy", "eighty", "ninty" };
	        thousands =
	        {
	            short = { "thousand", "million", "billion", "trillion", "quadrillion", "quintillion", "sextillion", "septillion" };
	            long = { "thousand", "million", "thousand million", "billion", "thousand billion", "trillion", "thousand trillion", "quadrillion" };
	        };
	        decimal =
	        {
	            short = { "thousandth", "millionth", "billionth", "trilionth", "quadrillionth", "sextillionth", "septillionth" };
	            long = { "thousandth", "millionth", "thousand-millionth", "billionth", "thousand-billionth", "trilionth", "thousand-trillionth", "quadrillionth" };
	        };
	    };
	
	    local function _raw_convert(n)
	        local r = { };
	        for i = #n, 1, -3 do
	            local val_p = tonumber(n:sub(math.max(i - 2, 1), i));
	            local val_p_r = numbers.ones[val_p];
	            if not val_p_r then
	                if val_p >= 20 then
	                    local h = '';
	                    if val_p >= 100 then
	                        h = numbers.ones[math.floor(val_p / 100)] .. ' hundred and ';
	                    end;
	                    val_p_r = h .. (numbers.tens[math.floor((val_p % 100) / 10)] or '') .. '-' .. (numbers.ones[val_p % 10] or '');
	                end;
	            end;
	            val_p_r = (val_p_r or ''):gsub("[- ]+$", "");
	            if val_p_r ~= '' then
	                val_p_r = val_p_r .. ' ' .. (numbers.thousands[context.scale][(#n - i) / 3] or '');
	                table.insert(r, 1, (val_p_r:gsub("[- ]+$", "")));
	            end;
	        end;
	        return table.concat(r, ', ');
	    end;
	
	    if type(value) == 'number' then
	        value = ("%.99f"):format(value);
	    end;
	    local int_v, frac_v = value:match("(%d*)[.]?(%d*)");
	    local int_r = _raw_convert(int_v:gsub("^0+", ''));
	    local frac_r;
	
	    frac_v = frac_v:gsub("0+$", '');
	    local frac_r = '';
	    if #frac_v > 0 then
	        if context.decimal == 0 and not context.financial then
	            frac_r = { };
	            for n in frac_v:gmatch('%d') do
	                table.insert(frac_r, numbers.ones[tonumber(n)]);
	            end;
	            frac_r = table.concat(frac_r, ' ');
	        elseif context.decimal == 1 and not context.financial then
	            local d = "tenth";
	            if #frac_v == 2 then
	                d = "hundredth";
	            elseif #frac_v > 2 then
	                d = (((#frac_v % 3) == 2 and 'hundred-') or ((#frac_v % 3) == 1 and 'ten-') or '') .. (numbers.decimal[context.scale][math.floor(#frac_v / 3)] or '');
	            end;
	            frac_r = _raw_convert(frac_v)
	            if frac_r ~= '' then
	                frac_r = frac_r .. ' ' .. d .. ((frac_v:gsub("[13579]", '') == frac_v) and '' or 's');
	            end;
	        else
	            frac_r = frac_v:gsub("^0+", '') .. '/1' .. ('0'):rep(#frac_v);
	        end;
	    end;
	
	    if int_r == '' and ((context.decimal == 0) or (#frac_r == 0)) then
	        int_r = 'zero';
	    end;
	
	    if #frac_r == 0 then
	        return int_r;
	    else
	        return ("%s %s %s"):format(int_r, context.decimal == 0 and 'point' or 'and', frac_r);
	    end;
	end;

[TheEdgyDev]

Can you explain what type the value and context parameters are?

[Blockzez]

The value paramter could be string or float and if float is converted to string while the parameter context is a table.

[TheEdgyDev]

Furthermore, what fields do you expect in the context table?

[Blockzez]

None really, it’s optional. (30 character)

[TheEdgyDev]

Do you convert any negative numbers or is it strictly 0 and positive numbers?

Also, to what decimal point are you targetting? Is it only integers?

I’m asking since displaying “x millionths” doesn’t sound like a good UX decision.

[Blockzez]

Only positive numbers and zzro.

and it targets up to 24 decimal places. I originally wanted it to be only positive integers but I added this for fun.

[phyouthcenter1]

I have created an updates version of this script.
It is now using grammar so the first version would say “one” but this version would say “One.”

function ToWord(value, context)
	context = context or { financial = false; scale = 'long'; decimal = 0; };
	context = { scale = context.scale or 'long'; decimal = context.decimal or 0; };
	local numbers =
		{
			ones = { "One", "Two", "Three", "Four", "Five", "Six", "Seven", "Eight", "Nine", "Ten", "Eleven", "Twelve", "Thirteen", "Fourteen", "Fifteen", "Sixteen", "Seventeen", "Eighteen", "Nineteen" };
			tens = { '', "Twenty", "Thirty", "Fourty", "Fifty", "Sixty", "Seventy", "Eighty", "Ninety" };
			thousands =
			{
				short = { "Thousand", "Million", "Billion", "Trillion", "Quadrillion", "Quintillion", "Sextillion", "Septillion" };
				long = { "Thousand", "Tillion", "Thousand million", "Billion", "Thousand billion", "Trillion", "Thousand trillion", "Quadrillion" };
			};
			decimal =
			{
				short = { "Thousandth", "Millionth", "Billionth", "Trilionth", "Wuadrillionth", "Sextillionth", "Septillionth" };
				long = { "Thousandth", "Millionth", "Thousand-millionth", "Billionth", "Thousand-billionth", "Trilionth", "Thousand-trillionth", "Quadrillionth" };
			};
		};

	local function _raw_convert(n)
		local r = { };
		for i = #n, 1, -3 do
			local val_p = tonumber(n:sub(math.max(i - 2, 1), i));
			local val_p_r = numbers.ones[val_p];
			if not val_p_r then
				if val_p >= 20 then
					local h = '';
					if val_p >= 100 then
						h = numbers.ones[math.floor(val_p / 100)] .. ' hundred and ';
					end;
					val_p_r = h .. (numbers.tens[math.floor((val_p % 100) / 10)] or '') .. '-' .. (numbers.ones[val_p % 10] or '');
				end;
			end;
			val_p_r = (val_p_r or ''):gsub("[- ]+$", "");
			if val_p_r ~= '' then
				val_p_r = val_p_r .. ' ' .. (numbers.thousands[context.scale][(#n - i) / 3] or '');
				table.insert(r, 1, (val_p_r:gsub("[- ]+$", "")));
			end;
		end;
		return table.concat(r, ', ');
	end;

	if type(value) == 'number' then
		value = ("%.99f"):format(value);
	end;
	local int_v, frac_v = value:match("(%d*)[.]?(%d*)");
	local int_r = _raw_convert(int_v:gsub("^0+", ''));
	local frac_r;

	frac_v = frac_v:gsub("0+$", '');
	local frac_r = '';
	if #frac_v > 0 then
		if context.decimal == 0 and not context.financial then
			frac_r = { };
			for n in frac_v:gmatch('%d') do
				table.insert(frac_r, numbers.ones[tonumber(n)]);
			end;
			frac_r = table.concat(frac_r, ' ');
		elseif context.decimal == 1 and not context.financial then
			local d = "tenth";
			if #frac_v == 2 then
				d = "hundredth";
			elseif #frac_v > 2 then
				d = (((#frac_v % 3) == 2 and 'hundred-') or ((#frac_v % 3) == 1 and 'ten-') or '') .. (numbers.decimal[context.scale][math.floor(#frac_v / 3)] or '');
			end;
			frac_r = _raw_convert(frac_v)
			if frac_r ~= '' then
				frac_r = frac_r .. ' ' .. d .. ((frac_v:gsub("[13579]", '') == frac_v) and '' or 's');
			end;
		else
			frac_r = frac_v:gsub("^0+", '') .. '/1' .. ('0'):rep(#frac_v);
		end;
	end;

	if int_r == '' and ((context.decimal == 0) or (#frac_r == 0)) then
		int_r = 'zero';
	end;

	if #frac_r == 0 then
		local toSend = int_r.."."
		return(toSend);
	else
		return ("%s %s %s"):format(int_r, context.decimal == 0 and 'point' or 'and', frac_r);
	end;
end;

[D0RYU (nici)]

I have a much more efficient function that can handle small and huge numbers

you might want to look at this

UltiMath V1.1 - a successor to MathModule V3

this module is an improvement of MathModule V3

UltiMath Functions

ㅤChance Functions ㅤㅤMean UltiMath.Chance:Mean() will find the mean out of a set of numbers print(math.Chance:Mean( 1, 2, 3, 4, 5 )) --OUTPUT: 3 this outputs as 3 ㅤㅤMedian UltiMath.Chance:Median() will find the median out of a set of numbers print(math.Chance:Median( 1, 2, 3, 4, 5 )) --OUTPUT: 3 this outputs as 3 ㅤㅤMode UltiMath.Chance:Mode() will find the mode out of a set of values print(math.Chance:Mode(…

I can’t exactly get the code because I am on mobile right now, but you can easily look at the source code in the Convert module

[Blockzez]

You do realise this is over a year old?

Your implementation only accepts IEEE, no idea why did you say

@D0RYU

can handle small and huge numbers

Your implementation don’t accept Infinity and all 2⁵² NaNs and don’t account for subnormals nor negative zero.
You’re using floating point division which I always avoided because I needed it to be arbitrary precise.

[D0RYU (nici)]

@Blockzez

Infinity

that’s impossible, not a number

@Blockzez

You do realise this is over a year old?

I decided to post it because @phyouthcenter1 replied a year later

@Blockzez

all 252 NaNs and don’t account for subnormals nor negative zero.

I never even noticed that I missed negative zero, tysm

also it can do any whole number up to 4 nonillion, could you please tell me what doesn’t work so I can improve it, thanks

@Blockzez

You’re using floating point division which I always avoided because I needed it to be arbitrary precise.

Actually, I am not using floating point division, did you actually look into what my code does?

anyways I took this as feedback on how to improve it, thanks

EDIT: I tested it and I guess if a decimal started with a 1 then it wouldn’t be right, looks like it was a simple ternary mistake

so if you try “0.1…” just wanted to let you know it won’t be right for now because I am not updating the module yet